1. Technical Field
The present invention relates to a method for testing preferably moving products having at least two layers, in particular packages wrapped with film, preferably cigarette packages, wherein at least one layer of the product, which is arranged further inwards,—the inner layer—, is covered at least regionally by at least one, at least partially transparent product layer, which is arranged further outwards,—the outer layer. The invention further relates to a device for testing such products.
2. Prior Art
Cigarette packages are typically provided at the end of manufacture with labels, coupons or other cut blanks. Subsequently they are wrapped with a transparent film. Automated optical testing of the cigarette package, in particular of said cut blanks, for defects is extremely difficult once the package has been wrapped with film. This is because reflections from the film interfere with the optical tests, for example by means of a camera.
It can also be difficult to carry out an automated optical test of the film itself. This is because images of the film, recorded by cameras, are superposed by images of the cigarette package situated under the film.